Amphibian Population Declines

The current rate of extinction is estimated to be greater than any known in the past 100,000 years . As a part of this "biodiversity crisis", amphibian populations around the world are experiencing declines. Amphibians are ecologically important because of their role as biological indicators of environmental stress . Factors affecting amphibians may also affect other animals, plants, and humans. Scientists have postulated a number of reasons for amphibian population declines including habitat loss, introduced species, global environmental change, diseases, and contaminants . Many of these hypthesized agents of declines may act synergistically in natural systems. Most work on amphibian population declines has focused on experimental manipulation of one or more factors believed to be involved with the declines. Understanding how these experimental manipulations scale up into population-level effects is well-suited to the spatial analysis tools within many GIS packages.